After a day of news saturated with images of smoking plane wreckage and reports that perhaps dozens of his fellow HIV researchers heading to the 2014 AIDS conference in Melbourne may have been on board Flight MH17, Richard Elion had to board a long flight from Los Angeles to Australia.

“I am about to leave for Melbourne,” Elion, an HIV specialist and clinical research director at Whitman-Walker Clinic in Washington, wrote from his iPhone Thursday night on his way to the airport in Los Angeles.

“It is hard to get excited about sharing information yet without a time to mourn,” he wrote. “It is very sad and will cast a pallor over the meetings.